Air valves—also commonly called “valve stems,” for tubeless tires are ubiquitous and are used for all kinds of tires for all kinds of vehicles from bicycles to motorized vehicles. Described generally, an air valve for a tubeless tire is a device that allows the tire to be inflated and deflated on the wheel; because the tire is tubeless, the valve provides an airtight fit where the valve is retained in the wheel or rim. The airtight seal between the air valve and the rim where the valve extends through the rim is very important to maintain proper air pressure in the tire without air leaks. There are a variety of known air valve designs for providing a seal at the interface between the rim and the valve, but in most cases there is some type of rubber housing or body on the air valve that is compressed against the opening or bore in the rim through which the air valve extends.
All air valves have in inlet opening, an air passageway through the valve, and an air outlet that is in the space bounded by the tire and rim where the pressurized air of the inflated tire is retained—“inlet” and “outlet” as used herein are relative terms and in this specification refers to the condition when air is being filled into the tire. The “inlet” is thus where air enters the air valve and the “outlet” is where air exits the valve. Of course, when a tire is being deflated the air flow through the air valve reverses—the “outlet” thus becomes the “inlet” and the “inlet” the “outlet.” Nonetheless, for purposes herein these relative terms are used to describe the airflow direction as a tire is inflated.
Once an air valve has been installed in a rim and a tire has been mounted to the rim, the tire is inflated by attaching a pressurized air source to the external portion of the air valve and passing pressurized air from the air source through the inlet opening, through the air passageway and into the tire through the air outlet. Most air valves have an internal air shut-off valve that is opened when the source of pressurized air is attached to the external end of the valve—i.e., the inlet. Once the tire has been inflated to the desired pressure the air source is detached from the air valve, and the internal shut-off valve is closed to prevent air from escaping and the tire is ready for use; typically, the higher pressure within the bounded space relative to the pressure outside of the tire pushes the internal shut-off valve into the closed position. Often, a secondary mechanism is engaged to prevent the internal shut-off valve from opening during use.
The air passageway through known air valves is a linear bore that runs through the valve shaft from inlet to outlet; this arrangement is well known and works very well.
Recently, certain improvements have been developed for tubeless tires that result in far better performance, but which complicate the process of inflating and deflating the tire. One specific example is the tire insert that is described in (a) U.S. patent application Ser. No. 14/656,250, now U.S. Pat. No. 10,293,640, (b) International Patent Application No. PCT/US2015/020213 (published at WO 2016/048409 A1), and (c) U.S. patent application Ser. No. 15/348,662, now U.S. Pat. No. 10,286,736, all of which are assigned to the assignee of and applicant for the present application and the entire contents of which are incorporated herein by reference. As described and shown in the referenced patent applications an annular member is disposed between the rim and the tire and provides significant functional and performance improvements. Notably, review of the drawings of the patent applications referenced above in this paragraph shows that the internal end of the valve stem—that is, the outlet of the valve stem through which air flows into the tire as the tire is being inflated, abuts or is in close proximity to the annular member that encircles the rim and is in the interior of the tire. This contact or close proximity typically is not a problem with the tire is being inflated since pressurized air flowing through the air valve tends to push the flexible annular member away from the air valve. However, since the annular member is flexible, it may tend to collapse or move toward the air valve as the air pressure in the tire decreases (such as when the tire is being deflated) and thus occlude or otherwise block the air passageway through the valve stem of a conventional air valve with a linear air passageway. More specifically, with an annular insert such as that shown in the referenced patent applications it may be fairly simple to inflate the tire, but deflating the tire can be made difficult given the obstruction of the air passageway at the inner end of the valve stem, which could be blocked by the annular member.
The present invention defines a novel and unique air valve that has a specially configured air passageway that allows a tire to be inflated and deflated even when the internal end of the valve stem is occluded and blocked, for example, when the internal end of the valve stem is in contact with an internal structure in the tire, such as the annular member described in the three patent applications that are incorporated herein.